clc
clear

R  = 6371229;  % average earth radius
Re = 6378137; % earth radius on equator
Rp = 6356752; % earth radius on pole

g  = gravitational_acceleration(R);
ge = gravitational_acceleration(Re);
gp = gravitational_acceleration(Rp);

Rpl = Rp;
Rph = Rp+5000;
gph = gravitational_acceleration(Rph);

ratio_ep = abs( ge - gp ) / gp;

function g = gravitational_acceleration(R)
G  = (6.674184*10^-11+6.674484*10^-11)/2;
me = 5.972*10^24;
g  = G*me/R^2;
end